Acta Chim. Sinica ›› 2016, Vol. 74 ›› Issue (8): 676-682.DOI: 10.6023/A16050268 Previous Articles     Next Articles



邵绒, 杨鑫博, 尹世伟, 王文亮   

  1. 陕西省大分子科学重点实验室 陕西师范大学化学化工学院 西安 710119
  • 投稿日期:2016-05-30 发布日期:2016-08-10
  • 通讯作者: 王文亮
  • 基金资助:

    项目受国家自然科学基金(Nos. 21173139,21473108)和陕西省重点科技创新团队基金(No. 2013KCT-17)资助.

Molecular Design of Benzothiadiazole Derivatives Electron Acceptors and Matching of Donor-Acceptor Materials

Shao Rong, Yang Xinbo, Yin Shiwei, Wang Wenliang   

  1. Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an 710119, China
  • Received:2016-05-30 Published:2016-08-10
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21173139, 21473108) and Shaanxi Innovative Team of Key Science and Technology (No. 2013KCT-17).

To better understand the relationships between the microstructure and the optoelectronic characteristics of the electron acceptor and to meet the needs of donor-acceptor materials with excellent optical properties for solar cell, a series of acceptor molecules with A'-π-A-π-A' type are designed. In these molecules, the core framework of benzothiadiazole is used as an acceptor (A), three kinds of conjugated heterocyclics (A') with different abilities of electron-withdrawing and steric effects are applied as the terminals, and various conjugated structures, such as the double bond, thiophene, benzothiophene and vinyl thiophene, are utilized as π-bridge, respectively. Their geometric configurations, the characteristics of frontier molecular orbital, optical properties, as well as the electronic reorganization energy are predicted by DFT-B3LYP and TD-DFT-CAM-B3LYP. Solvent effects from acetone and chlorobenzene on molecular properties are studied. Furthermore, the Donor-Acceptor (D-A) interfaces are respectively constructed by combining the excellent acceptors with the selected two donors. The DFT-D3 method is used to scan the binding energy of D-A complex, in order to determine the stacked displacement of the interface. The degree of interface recombination is evaluated by calculating electronic coupling (Vif) between HOMO of donors and LUMO of acceptors. The results show that modifying benzothiadiazole with a reasonable substituent is an effective way to adjust LUMO energy levels and lead to the noticeable variation of the energy gap. Combining planar electron acceptor materials (A'-π-A-π-A' type) with non-planar electron donor materials (D), to form the optical active layer is a practical approach for preventing interface recombination and achieving high open-circuit voltage (Voc). Considering ΔEL, Vif, light absorption efficiency, and solvation effect, D1-1aγ and D1-2aγ combinations are the most promising candidates of optical active layer materials in organic solar cell.

Key words: benzothiadiazole derivatives, electronic acceptors, Donor-Acceptor interface, electronic coupling, the power conversion efficiency